Our UK Pat. No. 1438293 describes a television system in which two parts of a relatively wide scene--such as six people seated at a conference table--are viewed by separate cameras. The resultant video signals are combined in that the central 50 percent of the active lines of each individual picture form respectively the upper and lower halves of the composite picture. The single combined signal may be displayed in this form or the two halves of the image can be separated and displayed on a pair of monitors mounted side-by-side.
A known arrangement of this type is depicted in FIG. 1 in plan view where first and second cameras 1,2 mounted at the same height have fields of view (which cross, as shown) covering two halves of a table 3 at which are seated six persons 4. The transmitted picture 5 and two-monitor display 6,7, after separation by a separator 8, are illustrated in FIG. 2. This system allows a maximum of a 4-line gap (arrow 9) between the two images.
One problem with such a system is that even with good quality cameras, regularly adjusted, colour drift can occur to a degree which, though not subjectively noticeable on a single picture, is apparent when images from the two cameras are viewed simultaneously.
The present invention aims to provide a composite signal from a single camera, and is defined in the appended claims.